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Author (up) Plotnik, J.; Nelson, P.A.; de Waal, F.B.M.
Title Visual field information in the face perception of chimpanzees (Pan troglodytes) Type Journal Article
Year 2003 Publication Annals of the New York Academy of Sciences Abbreviated Journal Ann N Y Acad Sci
Volume 1000 Issue Pages 94-98
Keywords Animals; *Facial Expression; Pan troglodytes; Recognition (Psychology); Visual Fields/*physiology; Visual Perception/*physiology
Abstract Evidence for a visual field advantage (VFA) in the face perception of chimpanzees was investigated using a modification of a free-vision task. Four of six chimpanzee subjects previously trained on a computer joystick match-to-sample paradigm were able to distinguish between images of neutral face chimeras consisting of two left sides (LL) or right sides (RR) of the face. While an individual's ability to make this distinction would be unlikely to determine their suitability for the VFA tests, it was important to establish that distinctive information was available in test images. Data were then recorded on their choice of the LL vs. RR chimera as a match to the true, neutral image; a bias for one of these options would indicate an hemispatial visual field advantage. Results suggest that chimpanzees, unlike humans, do not exhibit a left visual field advantage. These results have important implications for studies on laterality and asymmetry in facial signals and their perception in primates.
Address Department of Animal Science, Cornell University, Ithaca, New York 14853, USA. jmp63@cornell.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0077-8923 ISBN Medium
Area Expedition Conference
Notes PMID:14766624 Approved no
Call Number refbase @ user @ Serial 175
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Author (up) Plotnik, J.M.; de Waal, F.B.M.; Reiss, D.
Title Self-recognition in an Asian elephant Type Journal Article
Year 2006 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.
Volume 103 Issue 45 Pages 17053-17057
Keywords Animals; Asia; *Behavior, Animal; Cognition; Elephants/*psychology; Female; Photic Stimulation
Abstract Considered an indicator of self-awareness, mirror self-recognition (MSR) has long seemed limited to humans and apes. In both phylogeny and human ontogeny, MSR is thought to correlate with higher forms of empathy and altruistic behavior. Apart from humans and apes, dolphins and elephants are also known for such capacities. After the recent discovery of MSR in dolphins (Tursiops truncatus), elephants thus were the next logical candidate species. We exposed three Asian elephants (Elephas maximus) to a large mirror to investigate their responses. Animals that possess MSR typically progress through four stages of behavior when facing a mirror: (i) social responses, (ii) physical inspection (e.g., looking behind the mirror), (iii) repetitive mirror-testing behavior, and (iv) realization of seeing themselves. Visible marks and invisible sham-marks were applied to the elephants' heads to test whether they would pass the litmus “mark test” for MSR in which an individual spontaneously uses a mirror to touch an otherwise imperceptible mark on its own body. Here, we report a successful MSR elephant study and report striking parallels in the progression of responses to mirrors among apes, dolphins, and elephants. These parallels suggest convergent cognitive evolution most likely related to complex sociality and cooperation.
Address Living Links, Yerkes National Primate Research Center, and Department of Psychology, Emory University, 532 North Kligo Circle, Atlanta, GA 30322, USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0027-8424 ISBN Medium
Area Expedition Conference
Notes PMID:17075063 Approved no
Call Number refbase @ user @ Serial 408
Permanent link to this record